Recently, large suburban commercial facilities have been expanded, and an increasing number of people buy commodities, food, and the like at those large commercial facilities, rather than at stores and the like within walking distance from residential areas. Many of such large commercial facilities are located in areas remote from residential areas and metropolitan areas and are provided with large parking spaces. Therefore, in many cases, it is convenient to use private cars as a means of transportation. This is a reason behind a recent upward trend in the number of private cars owned.
However, there is a problem such as an increase in the rate of occurrence of traffic accidents with an increase in the amount of traffic. A group of people who do not drive daily to commute to work, school, and the like but drive infrequently only on weekends and the like have a high probability of causing traffic accidents. Furthermore, how to reduce the rate of occurrence of traffic accidents is an issue to be addressed in anticipation of the coming super-aging society in the near future. Therefore, driving support systems for providing information about the surroundings to a driver or warning a driver by detecting danger, for example, are under development.
A navigation system is known as one type of driving support system. The navigation system is provided with a display device such as a liquid crystal display device and supports driver's driving by displaying a map, positional information, a route to the destination, traffic information, or the like in a display portion of the display device.
As typical display devices, a liquid crystal display device, a light-emitting device including a light-emitting element such as an organic EL (Electro Luminescence) element or a light-emitting diode (LED: Light Emitting Diode), an electronic paper performing display by an electrophoretic method or the like, and the like can be given.
For example, in a basic structure of an organic EL element, a layer containing a light-emitting organic compound is provided between a pair of electrodes. By applying voltage to this element, light emission from the light-emitting organic compound can be obtained. A display device including such an organic EL element needs no backlight which is necessary for liquid crystal display devices and the like; therefore, thin, lightweight, high contrast, and low power consumption display devices can be realized.
Patent Document 1 discloses a flexible active matrix light-emitting device in which a transistor serving as a switching element and an organic EL element are provided over a film substrate.